2020  1,374
2019  1,023
2018  0,932
2017  0,977
2016  0,799
2015  0,662
2014  0,740
2013  0,739
2012  0,637
2011  0,658
2010  0,654
2009  0,570
2008  0,849
2007  0,805
2006  0,330
2005  0,435
2004  0,623
2003  0,567
2002  0,641
2001  0,490
2000  0,477
1999  0,762
1998  0,785
1997  0,507
1996  0,518
1995  0,502
Vol 53(2019) N 3 p. 393-401; DOI 10.1134/S0026893319030105 Full Text

Н.X. Liang1*, Н.W. Liu2

Inducible Expression of Ran1 and Its GDP- and GTP-Bound Mimetic Mutants Leads to Defects in Amitosis and Cytokinesis with Abnormal Cytoplasmic Microtubule Assembly

1School of Biomedical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024 China
2College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan, Shanxi, 030024 China

*lianghaixia456@hotmail. com
Received - 2018-06-06; Revised - 2018-10-16; Accepted - 2018-10-16

Ran is an evolutionarily conserved GTPase crucial in regulating various cell divisions, including mitosis and meiosis. A previous study showed that the knockdown of RAN1 inhibited macronuclear amitosis with the abnormal organization of intramacronuclear microtubules in Tetrahymena thermophila. This study aimed to further investigate the effects of the inducible expression of wild-type Ran1 (Ran1WT), GTP-bound Ran1-mimetic (Ran1Q70L), and GDP-bound Ran1-mimetic (Ran1T25N) on cytoplasmic microtubule assembly during amitosis of T. thermophila, based on previous studies about their effects on intramacronuclear microtubule. The mutant strains of T. thermophila for inducible expression of Ran1WT/T25N/Q70L by Cd2+ were constructed. The inducibly expressed HA-Ran1Q70L/T25N distributed asymmetrically across the macronuclear envelope during amitosis. At the lower level of inducible expression, only Ran1T25N showed a significant decreasing effect on T. thermophila reproduction, macronuclear amitosis and cytokinesis. At the higher level of inducible expression, Ran1WT/Q70L/T25N inhibited T. thermophila reproduction, macronuclear amitosis and cytokinesis, and the inhibitive effect of Ran1T25N was the most significant. The inducible expression of Ran1WT/Q70L/T25N led to defects in amitosis and cytokinesis with abnormal cytoplasmic microtubule assembly. These results further confirmed the regulatory function of Ran1 on amitosis and suggested a novel role of Ran1 in cytokinesis and the alignment of cytoplasmic microtubules in T. thermophila.

amitosis, cytokinesis, cytoplasmic microtubule, GDP/GTP-bound Ran1-mimetic, Ran GTPase